A funeral service is being held in Sydney today for Andrew Chan, and thousands are expected.

Andrew Chan's widow will read parts of the last letter she received from him on Indonesia's death row.

Reverend Christine Buckingham was with him and Myuran Sukumaran till the end.

She acknowledges it's a chance for the public to grieve.

"What you've got to remember is that Australia really at the core believes in second chances, and so it's more than just about the boys, this is about opportunity for them to connect with the injustice ice that is actually happened."

The funeral for Myuran Sukumaran will be held in Sydney tomorrow.